12 
SOUTH-AEEICAN BUTTERFLIES. 
TMs is especially noticeable in the ButterflieSj and reaches its maximum 
in the Morpliitoe of tropical South America, in many species of which 
magnificent group it is difficult to comprehend how the small slender 
thorax can contain sufiicient muscular power to work the enormous 
wings."^ The scales, which give to these organs their infinite variety 
of colouring and marking, and to the Order its name (XeTrlg, scale, 
irrepovy wing), are planted in the membrane by slender, very minute 
foot-stalks, and arranged so closely in transverse (not always quite 
straight) rows, that the basal portions of the scales of each row are 
hidden by the overlapping outer portions of those of the next row. 
These scales are in themselves objects of remarkable beauty under the 
microscope, their shape presenting a wonderful variety of outline, and 
their surfaces being covered with raised longitudinal and transverse 
lines forming a reticulation of the utmost minuteness and delicacy.^ 
The entire Order consisting of insects which live solely on fluid 
nutriment, there is not much variation in the mouth-parts except as 
regards the adaptation of the trunk or haustellum (modified maxillse) 
to obtaining liquid from various sources. A certain number of Moths 
take no food, their trunk being rudimentary ; these mostly belong to 
the group Bomhyces^ of which the common Silkworm Moth is a familiar 
example. The great majority of Lepidoptera, however, is in the per- 
fect state dependent on the honey of flowers, and the trunk varies 
greatly in length in accordance with the form of the nectar-yielding 
blossoms frequented. The nectaries of many flowers are shallow and 
open, and to rifle these a short haustellum sufiices ; but where the 
honey lies in a long tubular receptacle, a proportionately elongated 
trunk is necessary. The greatest development of this kind is reached 
in the typical Sphingidce, or Hawkmoths, which are thus enabled to 
take their food on the wing, without settling, and to reach supplies 
shut out from all other members of their Order. Thus, the haustellum 
of the common and widely- distributed Unicorn Hawkmoth {Sphinx 
Convolvuli) is four inches long, or twice the length of the whole body ; 
and a huge South-American ally, Am2^ho7iyx Cluentius, has a trunk 
over nine inches in length. The in many ways aberrant Death's-Head 
Hawkmoth (Acherontia Atropos) — as well-known and much-dreaded in 
South- Africa as in other parts of the world — has, on the contrary, a 
short, stifi*, broad proboscis, specially adapted for piercing the waxen 
lid of, and abstracting the honey from the cell of the hive-bee. Again, 
various large Noctuce — such as the well-known South-African Achcea 
Chamceleon — are able to pierce the skins of peaches and other fruits, 
^ Thus in Morpho Iphictus the whole body is but an inch long, and the thorax less than 
half an inch long and a quarter of an inch in breadth, while the fore-wings not only expand 
six and a half inches from tip to tip, but are two inches broad at the outer edge, and the 
hind-wings are each two and a half inches long and two inches broad. 
2 A favourite " test object " for some powers of the microscope has long been the scale of a 
Morpho Butterfly, — a good glass giving clear definition of the delicate ridges on the surface 
of the scale. 
